7-Bromochromone → 7-bromo-3,4-dihydro-2H-1-benzopyran-4-one

HRID 1684871ノート

反応式

HRID 1684871 の反応式
[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:12])[CH:7]=[CH:8][O:9]2)=[CH:4][CH:3]=1.[H-].C([Al+]CC(C)C)C(C)C>C1COCC1>[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:12])[CH2:7][CH2:8][O:9]2)=[CH:4][CH:3]=1

参加物

4

反応物 2

HCID 186867527-BromochromoneHCID 21225700Diisobutylaluminumhydride

生成物 1

HCID 223357367-bromo-3,4-dihydro-2H-1-benzopyran-4-one収率 69%

試薬・触媒・溶媒 1

HCID 8028Tetrahydrofuran溶媒

反応条件

温度
-80 °C

実験手順

A solution of 7-bromo-4H-chromen-4-one (26 g, 116 mmol) in dry THF (500 mL) under nitrogen for 1 hr, cooled to −80° C., and 173 mL of diisobutylaluminium hydride (2M in Toluene) was added over 30 minutes. The reaction was stirred at the same temperature for 30 min, quenched with a SiO2 (52 g)/water (52 mL) suspension, and allowed to warm to 0° C. The solution was filtered, the SiO2 washed with EtOAc, and the combined filtrate was concentrated to dryness. The residue was dissolved in CHCl3 (400 mL), washed with 1N NaOH (300 mL), dried over Na2SO4 and concentrated. Purification by chromatography on SiO2 (60-120 mesh) EtOAc/Pet ether (gradient elution 0-15%) afforded 7-bromochroman-4-one 18.1 g (69%) a pale yellow solid. LCMS 229.0 (M+2H); 1H NMR (DMSO-d6) 7.64-7.67 (d, 1H), 7.32 (s, 1H), 7.22-7.25 (d, 1H), 4.53-4.57 (t, 2H), 2.76-2.80 (t, 2H).

後処理

  1. customquenched with a SiO2 (52 g)/water (52 mL) suspension
  2. temperatureto warm to 0° C
  3. filtrationThe solution was filtered
  4. washthe SiO2 washed with EtOAc
  5. concentrationthe combined filtrate was concentrated to dryness
  6. dissolutionThe residue was dissolved in CHCl3 (400 mL)
  7. washwashed with 1N NaOH (300 mL)
  8. dry with materialdried over Na2SO4
  9. concentrationconcentrated
  10. customPurification by chromatography on SiO2 (60-120 mesh) EtOAc/Pet ether (gradient elution 0-15%)

出典と根拠

ORDレコード
ord-171c7a47b8444c6bbc204f5f4fea7a7f
出典データセット
uspto-grants-2012_04
特許番号
US08147818B2

反応ノート

読み込み中…